超高钢筋混凝土烟囱爆破切口角度选取的研究  

Study on Selection of Blasting Incision Angle of Ultra-high Reinforced Concrete Chimney

作　　者：柴亚博 罗宁 袁翊硕 杨振 韩涛 曹祺[4] CHAI Ya-bo;LUO Ning;YUAN Yi-shuo;YANG Zhen;HAN Tao;CAO Qi(School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,Xuzhou 221116,China;Luoyang Yu hang Blasting Engineering Co.,Ltd.,Luoyang 471000,China;School of Energy Engineering,Huainan Vocational and Technical College,Huainan 232001,China)

机构地区：[1]中国矿业大学力学与土木工程学院,徐州221116 [2]深部岩土力学与地下工程国家重点实验室,徐州221116 [3]河南省洛阳宇航爆破工程有限公司,洛阳471000 [4]淮南职业技术学院能源工程学院,淮南232001

出　　处：《爆破》2023年第4期124-131,160,共9页Blasting

基　　金：国家自然科学基金项目(12072363);精细爆破重点实验室开发基金重点项目(BL2021-03);安徽高校自然科学研究重点项目(KJ2020A1160)。

摘　　要：爆破拆除典型钢筋混凝土烟囱过程中,切口角度的合理选择是爆破拆除成功的重要因素。为确定切口角度的选取范围,根据余留截面的受力和破坏特征,采取隔离法,建立应力求解和应力及弯矩条件的理论模型:推导出余留截面上任意角度位置的应力求解公式,并定义了一个修订系数k来表达非切口截面上部的筒体,对余留截面不同角度位置产生的压应力影响效果的差异;建立筒体倾倒的应力及弯矩条件,结合应力求解公式与倾倒条件得出切口角度的选取范围。结合实际工程案例进行分析,研究结果表明:随着切口角度的增大,最大拉应力、最大压应力以及切口上部筒体产生的弯矩均呈现增大的趋势,而余留截面的抵抗力矩则呈现减小的趋势;最大拉应力达到材料强度极限时可得到切口角度的选取上限,两种弯矩相等时即可确定切口角度的选取下限;切口角度的改变对应力变化的影响要大于切口高度。工程案例中实际切口高度选择为4.5 m的条件下,依据所建立的理论模型得到切口角度的选取范围为[198°,237.6°],而实际切口角度为216°,处于理论选取范围之内,进一步验证了理论模型的可靠性,以期待更广泛地应用并指导工程实践。The reasonable selection of the incision angle is an important factor for the success of blasting demolition of a typical reinforced concrete chimney.In order to determine the selection range of incision angle,the isolation method was adopted to establish a theoretical model according to the force and failure characteristics of the residual section.The solution formula of any angle position on the residual section was derived,and a revision coefficient k was defined to express the influence of the cylinder at the upper part of the unnotched section.Furthermore,the stress and bending moment conditions of the dumping cylinder were established,and the selection range of the incision angle was obtained by combining the solution formula and the damping conditions.The case study shows that with the increase of the incision angle,the maximum tensile stress,the maximum compressive stress and the bending moment generated by the upper cylinder of the incision tend to increase,while the resistance moment of the residual section tends to decrease.The upper limit of the selection of the incision angle can be obtained when the maximum tensile stress reaches to the material strength limit,and the lower limit can be determined when the two bending moments are equal.Changing the incision angle would have a greater effect on stress than changing the incision height.Under the condition that the actual incision height is 4.5 m in the engineering case,the selection range of incision angle based on the established theoretical model is 198°~237.6°,and the actual incision angle is 216°within the theoretical selection range,which further verifies the reliability of the theoretical model.More extensive application and guide engineering practice are expected.

关 键 词：钢筋混凝土烟囱 隔离法 应力及弯矩求解 应力及弯矩条件 切口参数 

分 类 号：TU746.5[建筑科学—建筑技术科学]